1 /* $NetBSD: buffer.h,v 1.1 2005/12/15 21:32:00 christos Exp $ */ 2 3 /*- 4 * Copyright (c) 2005 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Christos Zoulas. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the NetBSD 21 * Foundation, Inc. and its contributors. 22 * 4. Neither the name of The NetBSD Foundation nor the names of its 23 * contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 * POSSIBILITY OF SUCH DAMAGE. 37 */ 38 39 #include <stddef.h> 40 #include <stdio.h> 41 #include <stdlib.h> 42 #include <err.h> 43 44 struct buffer { 45 char *ptr; 46 char *bptr; 47 char *eptr; 48 }; 49 50 static void 51 buf_init(struct buffer *buf) 52 { 53 buf->ptr = buf->bptr = malloc(BUFSIZ); 54 if (buf->ptr == NULL) 55 err(1, "Cannot allocate buffer"); 56 buf->eptr = buf->ptr + BUFSIZ; 57 } 58 59 static void 60 buf_end(struct buffer *buf) 61 { 62 free(buf->bptr); 63 } 64 65 static void 66 buf_grow(struct buffer *buf, size_t minsize) 67 { 68 ptrdiff_t diff; 69 size_t len = (buf->eptr - buf->bptr) + 70 minsize > BUFSIZ ? minsize : BUFSIZ; 71 char *nptr = realloc(buf->bptr, len); 72 73 if (nptr == NULL) 74 err(1, "Cannot grow buffer"); 75 76 if (nptr == buf->bptr) 77 return; 78 79 diff = nptr - buf->bptr; 80 buf->bptr += diff; 81 buf->eptr = buf->bptr + len; 82 buf->ptr += diff; 83 } 84 85 static __inline void 86 buf_putc(struct buffer *buf, char c) 87 { 88 if (buf->ptr >= buf->eptr) 89 buf_grow(buf, 1); 90 *buf->ptr++ = c; 91 } 92 93 static __inline void 94 buf_reset(struct buffer *buf) 95 { 96 buf->ptr = buf->bptr; 97 } 98 99 static __inline char 100 buf_unputc(struct buffer *buf) 101 { 102 return buf->ptr > buf->bptr ? *--buf->ptr : '\0'; 103 } 104